Fluorinated tackifier for pressure sensitive adhesives and pressure sensitive adhesives articles

Abstract

Described herein is a low molecular weight fluorinated (meth)acrylate polymer comprising a plurality of pendent sulfonylamide groups, which is used as a tackifier in a pressure sensitive adhesive composition. Also described herein is a pressure sensitive adhesive composition comprising the low molecular weight fluorinated (meth)acrylate polymer, and articles comprising the pressure sensitive adhesive composition. The pressure sensitive adhesive preferably also comprises a high molecular weight polymer, which is derived from a (meth)acrylate monomer or is a fluoropolymer.

1 . Use of a low molecular weight fluorinated (meth)acrylate polymer as a tackifier in a pressure sensitive adhesive composition, wherein the low molecular weight fluorinated (meth)acrylate polymer comprises a plurality of pendent sulfonylamide groups. 
     
     
         2 . The use according to  claim 1 , wherein the pressure sensitive adhesive composition comprises a high molecular weight polymer, having a at least one Tg, which is at most 0° C. and a number average molecular weight of at least 20 kilograms/mole. 
     
     
         3 . The use according to  claim 2 , wherein the high molecular weight polymer is derived from a (meth)acrylate monomer. 
     
     
         4 . The use according to  claim 3 , wherein the (meth)acrylate monomer comprises at least one of: iso-octyl acrylate, 2-octyl acrylate, 2-ethylhexyl acrylate, 2-propylheptyl acrylate, octadecyl acrylate, stearyl acrylate, butyl acrylate, 2-methyl butylacrylate, C18 acrylate derived from Guerbet alcohols, 2-hetpyl undecanyl acrylate, and combinations thereof. 
     
     
         5 . The use according to  claim 2 , wherein the high molecular weight polymer is a fluoropolymer. 
     
     
         6 . The use according to  claim 2 , wherein the adhesive composition comprises 10 to 400 parts of the low molecular weight fluorinated (meth)acrylate polymer per 100 parts of the high molecular weight polymer. 
     
     
         7 . The use according to  claim 1 , wherein the low molecular weight fluorinated (meth)acrylate polymer has a glass transition temperature of −15° C. to 40° C. 
     
     
         8 . The use according to  claim 1 , wherein the low molecular weight fluorinated (meth)acrylate polymer has a number average molecular weight of 0.5 to 10 kilograms/mole. 
     
     
         9 . The use according to  claim 1 , wherein the low molecular weight fluorinated (meth)acrylate polymer comprises at least four and no more than 50 monomeric units. 
     
     
         10 . The use according to  claim 1 , wherein the low molecular weight fluorinated (meth)acrylate polymer comprises a segment according to formula I: 
       
         
           
           
               
               
           
         
         wherein R 1  is H or CH 3 ; R 2  is a linking group; R 3  is H or an alkyl group; R f  comprises a perfluorinated group; and n is at least 2. 
       
     
     
         11 . The use according to  claim 1 , wherein the low molecular weight fluorinated (meth)acrylate polymer is derived from a first monomer comprising a pendent sulfonylamide group and a second monomer, wherein the second monomer is selected from a (meth)acrylate. 
     
     
         12 . The use according to  claim 11 , wherein the low molecular weight fluorinated (meth)acrylate polymer is derived from at least 50% by moles of the first monomer. 
     
     
         13 . The use according to  claim 1 , wherein the high molecular weight polymer comprises a functional pendent group comprising at least one of —OH, —COOH, and combinations and salts thereof. 
     
     
         14 . The use according to  claim 1 , wherein the low molecular weight fluorinated (meth)acrylate polymer comprises a plurality of pendent sulfonylamide groups further comprises a pendent group comprising at least one of —OH, —COOH, combinations and salts thereof. 
     
     
         15 . The use according to  claim 1 , wherein the pressure sensitive adhesive composition is crosslinked. 
     
     
         16 . The use according to  claim 1 , wherein the pressure sensitive adhesive composition further comprises a crosslinking agent. 
     
     
         17 . The use according to  claim 1 , wherein the pressure sensitive adhesive composition further comprises a plasticizer. 
     
     
         18 . A pressure sensitive adhesive composition comprising:
 a high molecular weight polymer; and   10 to 400 parts of a low molecular weight fluorinated (meth)acrylate polymer per 100 parts of the high molecular weight polymer, wherein the low molecular weight fluorinated (meth)acrylate polymer comprises a plurality of pendent sulfonylamide groups to form a pressure sensitive adhesive.   
     
     
         19 . A pressure sensitive adhesive composition according to  claim 18  having dynamic mechanical properties measured at 25° C. such that
 G′ measured at an angular frequency of 0.01 rad/s is greater than 1×10 3  Pa, 
 G′ measured at an angular frequency of 100 rad/s is less than 1×10 6  Pa, 
 G″ measured at an angular frequency of 0.01 rad/s is greater than 1×10 3  Pa, and 
 G″ measured at an angular frequency of 100 rad/s is less than 1×10 6  Pa. 
 
     
     
         20 . A method of making a pressure sensitive adhesive, the method comprising: combining a low molecular weight fluorinated (meth)acrylate polymer having a plurality of pendent sulfonylamide groups with a high molecular weight polymer to form a pressure sensitive adhesive.